Marine Engine Coolant Temperature Sensor for MerCruiser 3.0L 4.3L 5.0L 805218T 805218
Marine Engine Coolant Temperature Sensor for MerCruiser 3.0L 4.3L 5.0L 805218T 805218
Product Overview
Marine engine coolant temperature sensor for MerCruiser 3.0 L, 4.3 L and 5.0 L engines — the sender that drives the dash gauge, replacing MerCruiser 805218 and 805218T. It also cross-references OMC and Volvo Penta 3850397, Sierra 18-7600, CDI Electronics E13-0009, Crusader 47002 and Mallory 9-42402. A failing sender reads low or not at all, so the gauge sits flat while the engine overheats, or it reads high and sends you chasing a cooling problem that is not there. This sensor is a drop-in replacement for MerCruiser 805218T with the same thread and connector, so no adapter or rewiring is needed.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Engine Coolant Temperature Sensor / Sender |
| Application | Coolant temperature |
| Engine Type | MerCruiser sterndrive and inboard |
| Displacement | 3.0 L, 4.3 L, 5.0 L |
| Fitting | Direct replacement, original thread and connector |
| Quantity | 1 piece |
| Country of Origin | Taiwan |
| Packaging | 15 x 18 x 3 cm (5.9 x 7.1 x 1.2 in) |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| MerCruiser | 805218, 805218T |
| OMC | 3850397 |
| Volvo Penta | 3850397 |
| Sierra | 18-7600 |
| CDI Electronics | E13-0009 |
| Crusader | 47002 |
| Mallory | 9-42402 |
Compatible Engines
| Brand | Displacement | Application |
|---|---|---|
| MerCruiser | 3.0 L | Coolant temperature sender |
| MerCruiser | 4.3 L | Coolant temperature sender |
| MerCruiser | 5.0 L | Coolant temperature sender |
| OMC | 3850397 cross-reference | Verify against your engine serial number |
| Volvo Penta | 3850397 cross-reference | Verify against your engine serial number |
Confirm the original part number on your engine or in your parts diagram before ordering — MerCruiser used more than one sender thread across the 3.0 L, 4.3 L and 5.0 L range.
What's Included
| Component | Qty |
|---|---|
| Engine Coolant Temperature Sensor (805218T) | 1 |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Before You Buy
- Verify the original part number on your engine before ordering — 805218 and 805218T are not interchangeable on every model
- Check the gauge wiring and the sender's single wire for corrosion first — a bad ground mimics a failed sensor
- Use a thread sealant rated for coolant on the sender, and do not overtighten into the cast housing
- Test the new sender before refilling: warm the engine and confirm the gauge climbs smoothly rather than jumping
- 30-Day Easy Returns
- Free Worldwide Shipping
- OEM Quality Without the Markup
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Before You Buy
Frequently Asked Questions
What is your refund policy?
We offer a 14-day hassle-free return on all products. Items must be unused and in original packaging. Every XRmarine part is also covered by our 1-year warranty against manufacturing defects. If something is not right, email us at info@xrmarineparts.com — replacement or full refund, your choice.
See our full Refund Policy for complete details.
How does shipping work?
Free international shipping on every order — no minimums. We operate a global warehouse network with a main distribution centre in Asia (10-20 business days). We also hold stock in regional warehouses across the United States, Germany, the United Kingdom, Australia, and Poland (opening soon) — most orders arrive in 1-3 business days within those countries and in 2-8 business days to nearby regions. Tracking included.
See our full Shipping Policy.
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